This invention relates to high speed pouch forming, filling and sealing and more particularly to convertible pouch filling and sealing methods for accommodating pouches of varied widths or pitch at speeds in excess of about 300 to 400 pouches per minute.
This application is related to applicant's copending applications as follows: "Convertible Pitch Pouch Knife", naming Paul E. Dieterlen as inventor; "Variable Count Direct Deposit Knife" by Paul E. Dieterlen; "Tuck Roller With Improved Web Tension Control", naming Martin Wildmoser and Frank Oliverio as inventors; and "Low Thermal Inertia Sealer", naming Martin Wildmoser as inventor, all filed on even date herewith and expressly incorporated herein by reference.
Current high speed pouch machines are capable of filling and sealing pouches at commercial speeds of, for example, two to four million pouches per week, based on single shift operation. While such machines represent a highly advanced stage of operational speeds, such machines are limited by tack of flexibility in pouch width or pitch (i.e. cut-off). While current high speed horizontal form fill and seal machines can easily deal with taller or shorter pouch changeovers, such as pouches from one inch to twelve inches tall, such machines are not easily convertible to changes in pitch at desirable commercial speeds.
Currently, a commercial pouch forming, filling and sealing machine is dedicated to one pouch width or pitch, with only slight available adjustment. Such a machine may cost in the range of something over $500,000 up to something less than $1,200,000. Purchasers or end users of such machines are thus constrained, by virtue of such capital investments, to certain pouch widths or pitch, with only minor variations, for significant periods of time.
While manufacturers might provide machine pitch conversion, this process generally has required a long and involved rebuild of the machine, taking at least four to six months and costing in the neighborhood, for example, of $300,000 to $400,000. This conversion would then be dedicated to the converted pitch.
Product marketers desire to be able to offer products in varied size (i.e. varied width) pouches. Future changes in market packaging configuration can quickly obsolete a given pouch width, and thus the associated dedicated width machine. Machines dedicated to given pouch widths preclude attempts to run special trial sizes or promotional pouches.
It will be appreciated then that dedication to a given pouch width generally requires the customization of each original pouch machine to such width. This, however, renders each machine more or less one of a kind, limiting its practical convertibility. For example, a pouch machine typically includes a web plow for folding a moving web onto itself, a vertical sealer, designed and dedicated to a given pitch, for creating vertical seals in the moving, folded web, a pouch filler wheel designed and dedicated to the selected pouch width or top sealer for opening and filling pouches between the seals, and a knife also designed and dedicated to the design pouch widths for cutting sealed pouches off the web train. One or more feed augers are used to introduce product into pouch filling spouts and into the pouches themselves.
A web of pouch material is thus typically folded on itself and sealed vertically to form given pitch, open ended pouches. These are filled, top sealed, and individual pouches are cut off from the pouch train by the knife, slicing down through the vertical seals. These various components have to be coordinated for speed consistency as each operates on the moving, unbroken pouch train.
Thus, the typical previous approach to pouch machines required that each machine be unique and custom built, designed and dedicated to a given pouch pitch. Even though the outward appearance from one machine to another often looked the same, the drive transmission, drive element positions and drive ratios were quite different, depending on the design pouch width. Due to this uniqueness, conversions to alternate pouch widths were difficult and expensive.
A brief explanation of several of the machine components will help provide further understanding of the pouch pitch conversion difficulties faced in the past.